Dialysis apparatus with capillary exchanger

ABSTRACT

MEMBRANE CAPILLARY EXCHANGERS INCLUDING MULTIPLE COUNTERCURRENT EXCHANGERS AND THE PROCESS FOR MAKING AND USING THEM ARE DISCLOSED IN THE PRESENT APPLICATION. THE MEMBRANE CAPILLARY IS PRODUCED BY DEPOSITION ONTO AN AUXILIARY CORE FOLLOWED BY BUNDLING A PLURALITY OF THE CAPILLARIES, INTRODUCING A MEANS FOR HOLDING INTO THE ENDS OF THE CORES, CASTING AND HARDENING THE MEANS FOR HOLDING TO THE ENDS OF THE CAPILLARIES, REMOVING THE MOLD AND THEN REMOVING THE AUXILIARY CORES FROM THE INTERIOR OF THE MEMBRANES. THE EXCHANGER IS OPERABLE IN THE CHAMBER FOR DIALYSIS LIQUID TREATMENT.

1972 HANS-JOACHIM DIETZSCH HAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet 1 INVENTORS Hans Jana/7 I'm Dfefzsch 0H0 D/efzsch /W'b Z M A TTORNE Y5 1972 HANS-JOACHIM DIETZSCH ETAL 3,70

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGEH Filed June 6. 1969 17 Sheets-Sheet 2 FIG.4

.Ih I in! INVENTORS Hans -J0ac him Diefzsch H0 y magft {P 202 621 ATTORNEYS Dl'efzsch Nov. 28, 1972 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGEH HANS-JOACHIM DIETZSCH ET AL 17 Sheets-Sheet 3 Filed June 6. 1969 FIG. 6

m 1/5 0195 Hans J0 och/m D iefzs c'h 0H0 Die/zsch yaa g b 201% ATTORNEYJ 28, 1972 HANS-JOACHIM DIETZSCH ETAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet 0.

mvzzv-rons Hans Joachim Die/zsc'h 02 f0 Diefzsch ATTORNEYS 1972 HANS-JOACHIM DIETZSCH ETAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet 5 FIG 13 1 I I l I llllmlllml llmlllfdlll IIIIMlIIEI F|G. FIGMb WIIIIIIIJ INVENTORS Hans Joachim Diefz 30 h 0 0 Die/ ach v ww ATTORNEYS Nov. 28, 1972 HANS-JOACHIM DIETZSCH ErAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet i INVENTORS Hans -J0ach/'m Diefzsch 02 f0 Diefzsch BY mafia: 1? 10% A T TORNEYS N 1972 HANS-JOACHIM DIETZSCH T 3,

nnm'srs APPARATUS wz'rn CAPILLARY EXCHANGER 1'7 Sheets-Sheet 7 Filed June 6. 1969 FIG. 2 0

FIG. 21

INVEN TORS Hans-Joachim Die fzsc'h 0H0 Die/25th W @P QJM A T TORNEKS 1972 HANS-JOACHIM DIETZSCH E ,7

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER 17 Sheets-Sheet 8 Filed June 6. 1969 FIG. 24

mvnvraks Hans J0ac/2im Die fzsch 0H0 Diefzsch W 1 204L684- ATTORNEYS Nov. 28, 1972 HANS-JOACHIM DIETZSCH EI' 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER l7 Sheets-Sheet 9 Filed June 6. 1969 IN VINTORS Hans-Joachim Die fzsch 0H0 Diefzsch W 70% A TTORNEVS 1972 HANS-JOACHIM DIETZSCH ETAL 3,704,323

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet 10 lfil 1 FIG.28

mvt/vmks Hans -J0 achi m D iefzsch 0H0 Dierzs c h ATTORNEYS N 1972 HANS-JOACHIM DlETZSCH EI'AL 3,704,323

DIALYSIS AITARATUS WITH CAPILLARY EXCHANGER 17 Sheets-Sheet 12 Filed June 6. 1969 FIG. 31

IN VB N TORS Difzsch 0H0 Die/25c y W t www Hans- Joachim A TI'ORNEYS 1972 HANS-JOACHIM DIETZSCH ErAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER l7 Sheets-Sheet 13 Filed June 6. 1969 a L m 2 5 mvnvraps Hans-Joachim Die/25d? 0H0 Diefzscb 7 1ft 1% 20M ATTORNEYS Nov. 28, 1972 HANS-JOACHIM DIETZSCH ETAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER 17 Sheets-Sheet 14 Filed June 6. 1969 HG. 35b

FIG. 35

,INVE NTORS Joachim Die 1256/7 Hans 1972 HANS-JOACHIM DIETZSCH EI'AL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Filed June 6. 1969 17 Sheets-Sheet 18 FIG. 37

INVENTORS Hans Joach I'm DiefZSc'h 0H0 D/efzsch W 2 $11 624 ATTORNEY;

N 1972 HANS-JOACHIM DIETZSCH ETAL 3,704,223

DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER l7 Sheets-Sheet 1 Filed June 6, 19 69 FIG. 380

FIG. 38b

INVEN TORS H ans hoa/Hm .Diefzsch 0H0 Diefzsch By if ZULM WTrORA/EVS N 1972 HANs-JOAcHIM DIETZSCH ETAL 3,704,223

DIALYSIS APPARATUS wrm OAPILLARY nxcamem Filed June 6. 1969 17 Sheets-Sheet 17 V //Y// //j///7] FIG. 39

INVENTORS Hans Joachim Diefzs ch 0H0 Diefzsch W ZUM ATTORNEYS United States Patent Ofice Patented Nov. 28, 1972 3,704,223 DIALYSIS APPARATUS WITH CAPILLARY EXCHANGER Hans-Joachim Dietzsch, Villars-sur-Ollon, Vaud, and

Otto Dietzsch, Stein am Rhein, sh, Switzerland Filed June 6, 1969, Ser. No. 831,174 Claims priority, application Switzerland, June 8, 1968, 8,632/68; Austria, May 27, 1969, 5,012/69 Int. Cl. B01d 13/00, 13/02; (30% 1/60 US. Cl. 204-301 14 Claims ABSTRACT OF THE DISCLOSURE Membrane capillary exchangers including multiple countercurrent exchangers and the processes for making and using them are disclosed in the present application. The membrane capillary is produced by deposition onto an auxiliary core followed by bundling a plurality of the capillaries, introducing a means for holding into the ends of the cores, casting and hardening the means for holding to the ends of the capillaries, removing the mold and then removing the auxiliary cores from the interior of the membranes. The exchanger is operable in the chamber for dialysis liquid treatment.

The invention concerns a process for the production of a capillary exchanger as well as the resultant improved exchanger obtained by this process.

Capillary exchangers have many applications, e.g. as exchangers for gases or components of solutions, for heat exchange and the like.

Capillary exchangers are already known which, however, have various shortcomings. Above all, it is the end face zone of the capillaries of such an exchanger with the necessary end plates in which the capillaries must be mounted that is often defective. The shearing stress on the capillaries in the area of the end plates is substantial and readily leads to breakage. In addition, leakage which is difficult to control often occurs at the mounting of the capillaries in the end plates.

It is therefore a first object of the present invention to eliminate such defects and to produce such capillary exchanger apparatus in an industrially feasible process for mass production distinguished by excellent tensile strength and stability of the mounting in the end plates.

The preferred mode of the process according to the invention leads to improved capillary exchangers which, in addition to the above-mentioned advantages also has the further advantage of an especially favorable flow in the exchangers interior. This advantage will be explained in detail further below.

The invention concerns primarily a process for the production of a membrane capillary exchanger having capillaries which are arranged side by side and spaced apart from each other, both ends of said capillaries being firmly embedded with their open end faces in holes of at least two holding walls, wherein each intracapillary space constitutes a passageway for a first liquid and the intercapillary space between the holding walls constitutes a passage for the flow of a second liquid and wherein each membrane capillary has been produced by the application, onto an auxiliary core consisting of a dissolvable or relatively easily fusible auxiliary substance, of at least one membrane layer, deposited from a solution of a substance capable of forming a membrane, or from a solution of an intermediary substance which is convertible into the final membrane substance, and, in the latter case, subsequent conversion into the final membrane substance, which process comprises (a) bundling a plurality of the membrane capillaries or intermediary product capillaries,

which capillaries contain the said auxiliary cores, while maintaining sufficient distances between the capillaries to allow the flow of the second liquid therethrough; and (b) introducing, in this arrangement the ends of the capillaries of said bundle into a holding means which is contained in a casting mold; (c) then pouring onto the holding means a layer of hardenable casting material which sealingly combines with the end zones of the capillaries; (d) hardening the resulting cast layer; then (e) removing the mold and the holding means contained therein from the capillary ends; and (f) finally removing from the interior of the membrane capillaries of intermediary substance the auxiliary cores, while preserving the outer layers constituting the membrane capillaries or the said intermediary substance capillaries.

In particular, the removal of the auxiliary core can be accomplished either by dissolving out the auxiliary core with a solvent which dissolves the said core but not the membrane capillary substance nor the said intermediary substance; or, in case the auxiliary core is made of a substance with a melting point below the melting point of the membrane capillary substance or the said intermediary substance, it can be melted out of the interior of the capillaries.

The finished capillary exchanger possesses then, as usual, an exchanging surface formed by the mantles of a plurality of hollow tubes or hollow threads which in the following are designated capillaries. These capillaries with their open end faces or the adjacent zones thereof are sealingly introduced or embedded in the end walls of the feed or collecting chambers and the exchange between the intraeapillary interior space of the capillaries and the intercapillary space, i.e. the space surrounding the capillaries, can take place in one or in both directions.

In the exchangers produced according to the invention, the capillaries are sealingly embedded in their end face zones in the walls or parts of the walls of the feed chambers or of the hardened casting material forming the intercapillary space.

In the process according to the invention the abovementioned membrane layers are applied to the auxiliary cores by lacquering or spraying them with drying and/or curable lacquers, casting resins or other resin forming liquid or pasty substances, such as, e.g., silicone rubber.

The application of one or preferably several coatings onto the auxiliary core is performed advantageously by using a solution of an intermediary substance which can be converted into the membrane substance, and the wall consisting of said intermediary substance is later converted by drying, curing or a suitable chemical treatment into the final substance forming the membrane capillary.

The dissolving or melting out of the auxiliary cores is preferably performed after the hardening of the layer or layers of casting material which form the walls of the intercapillary space or of a supply or collecting chamber or of a part of the wall of such a space.

According to the preferred embodiment of the process according to the invention, at least one of the two end face zones of each of the capillaries is coated on the outer circumference thereof with an auxiliary mantle, before the above-mentioned introduction into the holding means, thus improving the stability of the mounting of the capillaries in the layer of casting material.

Such auxiliary mantles are coatings applied to the capillaries, consisting, e.g., of lacquer, of casting resins capable of being hardened after application, or of deposits of metal, preferably having been produced electrolytically.

According to the invention, such auxiliary mantles substantially improve the adherence of the end face zones of the capillaries to the hardened layer of casting material surrounding them. This is, for example, the case when the auxiliary mantles consist of silicone resins or metal. On the other hand these auxiliary mantles substantially reinforce the capillary end face zones in the vicinity of the hardened cast layer which surrounds them. Preferably, the auxiliary mantles consist of lacquer components such as acetyl cellulose, of hardened layers of casting resins such as epoxed resins, or of metal.

According to a further specific embodiment of the process according to the invention, when the layer of casting material is poured onto the holding means to engage the capillary end, a preferably prefabricated frame surrounding the entire bundle of capillaries is also placed on the holding means about the ends of the membrane capillaries or intermediary capillaries of said bundle so that said frame is also joined with said cast layer. This frame can be provided with appropriate projecting rims or indentations which form-lock with the final hardened cast layer so that the frame and the cast layer are very firmly joined.

In the process according to the invention, the capillaries are bundled either in a two-dimensional arrangement so that, e.g., a single layer of capillaries arranged parallel to each other is obtained, or preferably in a three-dimensional arrangement in a plurality of layers. The individual capillaries are first inserted into spacing tubes and then optionally conducted from these into spacers which remain in the bundle at least until the layer or layers of casting material have been poured onto the holding means, or still better, until the layer or layers of cast material have been hardened.

The bundle of the capillaries which are in the holding tubes or the spacers can then be treated at both ends thereof as described above for casting the layer or layers of material in the end face zones of the capillaries.

The capillary ends of one end of the capillary bundle is preferably inserted vertically into the holding means, which consists of an easily formable substance which is always or temporarily a liquid, a paste or a gelatinous mass preferably having a smooth surface, whereby this substance must be inert to the capillaries and to the casting material used for the cast layer. The capillary ends of the bundle are, e.g., dipped or inserted into the holding means.

After the drying or hardening of the cast layer, the holding means is removed by simple measures such as by heating, or by dissolving in suitable solvents.

According to the invention, the capillaries are arranged into a bundle by first arranging the capillaries in a preferably single layer, which can be compared with the warp of a fabric as used in the textile industry, then cutting off segments of such a single-layered arrangement of capillaries, and combining a plurality of such segments to a bundle consisting of a plurality of layers.

The operations described below, which primarily concern the end zones of capillaries which have already been combined, are preferably performed on a single layer or row of capillaries. They can, however, also be performed on the multilayered bundle of capillaries.

Many of these operations, such as, e.g., lacquering, hardening of hardenable coating substances, metallizing, etc. are more readily performed on single layers than on multi-layered bundles.

According to the invention, spacers can be used to arrange the capillaries in bundles, which spacers remain in the bundle when the end face zones of the capillaries are cast with the casting substance; the spacers can then be removed from the bundle or left in.

A specific embodiment of the invention comprises casting the spacers together with the casting material, preferably in a layer of casting material in which, at the same time, a prefabricated frame is fixed.

The invention further concerns a novel multiple countercurrent exchanger which can be produced according to the above-described process, comprising a casing; a bundle of tubes, preferably capillaries, in said casing,

which are essentially parallel to each other; two end walls in one of which walls the one end of the said bundle of tubes is fastened, while the other end of said bundle is fastened in the other wall, the tubes of said bundle having orifices on the outward sides of said end walls; a chamber containing the said bundle therein extending between the two end walls; an arrangement for charging the tube openings on one end of the said bundle with a first fluid and for removing the latter from the tube openings at the other end of the bundle, as well as inlet means and outlet means, for the passage of a second fluid through the said chamber; an inset consisting of a plurality of walls forming between them a plurality of individual tubular channels being open at both ends, said inset being fastened in such a manner in the said chamber that through the interior of each of the said individual tubular channels there passes at least one of the said tubes, while in the zones of the interior of the said chamber adjacent to the said end walls there are free spaces, into which the orifices provided at both ends of the said individual tubular channels open, the said inlet means being connected with one of the free spaces and the said outlet means being connected with the other free space in the interior of the chamber.

In this multiple countercurrent exchanger according to the invention, the two end plates extend in two planes which are preferably not parallel with each other or which are curved, whereby the length of the tubes, in particular capillaries, of said bundle varies from one place to another.

The cross-section of each of the said individual channels of the inset preferably diminishes towards at least one of its two ends, in particular in the vicinity of that end of the inset which leads to the free space which is connected with the said fluid inlet means, the cross section being sufficiently narrow so that the second fluid introduced into the latter space is practically evenly distributed to all of the channels of the inset.

In a specific embodiment the said inset consists of a plurality of tubes being connected with each other in at least one zone, whereby the connection of the tubes of the inset, e.g., consists of at least one spacer. The walls of the inset can consist of a plurality of foils touching each other, at least a part of which are grooved or corrugated. On the other hand, the inset can consist of a block having individual channels formed by passages which run substantially parallel to each other.

In a preferred embodiment of the multiple countercurrent exchanger according to the invention, the tubes of the said bundle are thickened at at least one of the ends thereof, whereby the thickened portions extend through the end wall holding the respective ends of the tubes and reach into the interior of the individual channels of the inset surrounding the tubes.

The thickened ends of the tubes advantageously extend through the end wall located at the inlet side for the second fluid and into the interior of the individual channels surrounding the tubes, the cross section of which channels in the vicinity of the passage of the tubes therethrough is narrowed in such a way that the second fluid from the free space located at the inlet side is evenly distributed to all of the channels.

The individual channels are preferably provided with narrowed zones causing turbulence in the second fluid flowing therethrough, as well as other effects explained further below. The portions of the tubes which are within the channels can also be provided with narrowed zones, by means of which zones turbulence is caused in the first fluid flowing therethrough.

Embodiments of the invention with reference to the attached drawings illustrate the invention more in detail. For the sake of clarity, the drawings are in places distorted and out of proportion, they also contain fewer elements than in practice. Thus the number of capillaries in the single warp beam" layer of capillaries can be several thousand, the number of capillaries per exchanger bundle several hundred thousand.

In the drawings:

FIG. 1 shows in perspective a partial view of an apparatus for bundling the capillaries;

FIG. 2 shows the same apparatus in lateral section;

FIGS. 3 to 7 show various steps for the introduction of the capillary bundle into the spacers;

FIGS. 8 to 11 show the various steps for the application of a layer of casting material;

FIG. 12 shows a specific embodiment corresponding to FIG.

FIGS. 13 to 15 show various embodiments and the use of spacers;

FIGS. 16 to 19 show the individual steps of modifications in the process after removal of the holding means;

FIGS. 20 to 23 show the application of a layer of casting material after auxiliary mantles have been applied to the end face zones of the capillaries;

FIGS. 24 to 29 show the corresponding steps when a frame is used;

FIG. 30 shows a preferred embodiment of a novel multiple countercurrent exchanger produced according to the invention;

FIG. 31 shows a specific construction of inset tubular channels for such an exchanger;

FIGS. 32, 33 and 34 show other modified embodiments of such an exchanger;

FIGS. 35, 35a, and 35b illustrate modification of the process according to the invention for the production of capillaries with unsymmetrical cross-sectional properties;

FIGS. 36 and 37 show arrangements for the production of capillaries according to FIGS. 35, 35a and 35b;

FIGS. 38a and 38b illustrate the assemblage of several such capillaries according to FIGS. 35, 35a and 35b; and

FIG. 39 illustrates the operative characteristics of a bundle of capillaries according to FIGS. 35, 35a and 35b when used for electrodialysis.

FIG. 1 shows such a warp beam"-type of single-layer, side-by-side arrangement of capillaries 1 on a roller 2. This single layer arrangement of the capillaries is unrolled from this roller in the direction of the arrow 3, conveyed to a storage holder 4 and inserted into it. The storage holder 4 consists of a plurality of rows of bores 5, which for example can be formed by a corresponding arrangement of rows of tubes 6. Advantageously, each bore 5 corresponds to one capillary 1.

The introduction of the capillaries 1 into the storage holder 4 is preferably accomplished by filling one row at a time of the bores 5 with a layer of the capillaries 1. For this purpose the capillaries are led through a guide plate 7 provided with holes 5', which can be moved parallel to itself in the direction of the double arrow 8.

After one layer of capillaries has been inserted into the storage holder, the knife 9 (not shown in FIG. 1, see FIG. 2) cuts off this layer of capillaries at position 10.

After moving the guide plate 7 the distance of one row of bores, the process described for introducing the capillaries can be repeated. The layer of capillaries can be transported for the introduction into the storage holder by means of the pair of rollers 11 (also only shown in FIG. 2), which is accordingly driven intermittently in the direction of rotation of arrow 12.

FIG. 2 shows schematically a side view of the same apparatus as is shown in FIG. 1. In FIG. 1 only the front portion of the storage holder 4 is shown in perspective view, FIG. 2 shows its whole length. In both figures the lower row of the bores S are already filled with capilaries 1. The capillaries 1 are shown as lines. For clarity, the same linear representation of the capillaries has been chosen for FIGS. 3 to 22, 28 and 34.

Preferably the bores 5 are open at both ends of the storage holder 4 and the length of the storage holder is less than the length of the capillary segments, so that these, as shown in FIG. 3, can protrude a short distance from both ends of the storage holder.

Furthermore, it is suggested that the rear ends 13 of the bores 5 or the tubes 6 are tapered or bent inwardly so that their rear orifices are narrower than their front orifices.

After the storage holder 4 has been completely filled with capillary segments 1, as shown in FIG. 3, spacers 14, consisting, for instance, of one or more woven pieces, the apertures of which are of the same size or larger than the diameter of the capillaries 1, while the distance between the apertures corresponds to the spacing of the bores of the storage holder, which spacers are located at one end of the storage holder, are appropriately brought into position (FIG. 4), advantageously at the end at which the tapered ends 13 of the bores are to be found.

In FIG. 4 the following process step is illustrated: the capillaries 1 are inserted by the pusher 15 through the storage holder and the front ends thereof are pushed into the spacers 14 to be in frictional engagement with the latter. Then all of the capillaries are drawn with the aid of the spacers 14 to the left in FIG. 6, i.e. out of the storage holder; at the same time or subsequently the spacers are distributed over the entire length of the bundle of capillaries until the latter are finally borne only by the spacers 14, namely, after the capillaries have been completely withdrawn from the storage holder (FIG. 7). These operations can be performed by hand or these movements can also be carried out automatically by known mechanical means (not shown). It is also possible to place the capillaries directly into the spacers without the intermediary use of a storage holder.

FIGS. 8 to 11 show the subsequent operations to which the capillary bundle is then subjected. In FIG. 8 this bundle is placed with the capillaries in vertical position above a layer of a holding means or agent 17 having an even and smooth surface, which has been poured into a trough 16. The lower ends of the capillaries are dipped or inserted into this layer of holding agent (FIG. 9). Then, as shown in FIG. 10, a layer 18 of casting material is poured onto the surface of the holding layer 17 and between the capillaries, and the cast layer is then hardened in the mold constituted by the surface of the holding agent 17 and the walls of trough 16. After this hardening process, or also during it, the capillary bundle together with the said poured-on and hardened layer 18 of cast material is withdrawn from the holding means 17 (FIG. 11).

After these operations have been completed, the other end of the capillary bundle can also be provided with a layer of hardened casting material in the same manner as described above and illustrated in FIGS. 8 to 11, by rotating the bundle by and repeating these steps.

FIG. 12 shows a modification of this process leading to another form of the exchanger, wherein the capillaries are closer to each other in their end face zone than in the adjacent zone of the exchanger. If, on the other hand, it is desirable to have the capillaries equally spaced apart, in the zone in which they are embedded in the terminal face walls as well as in all other zones of the exchanger, the process steps shown in FIGS. 8 to 11 will afford this result. An embodiment of a capillary exchanger according to the invention in which the capillaries are arranged to meet this requirement illustrates a preferred feature of the invention.

The spacers 14 can, for example, remain or be removed after the production of the layers of hardened cast material 18. This can be removed by pulling out the spacers or by dissolving them in a solvent.

Spacers can be, for instance, perforated sheets or woven material, as shown in section in FIG. 13, or combs the teeth of which have been laid across each other, as shown in FIGS. 14a and 14b (separated position) and FIG. 14 (crossed position, in which the capillaries 1 have been inserted). In some of the apertures of the spacers accord- 

